This is my first time using elk 5.5 for gathering tweets from twitter, everything is ok and works fine.
In order to handle my application, I need to make the filed text (tweets ) as an aggregatable field, i tried to add raw field to text but nothing happened.

Use type "keyword" and drop the "index not analyzed" part on your "raw" fields.
However, I'd question the logic behind wanting to do this as this will introduce many largish fields into your index.
What business problem are you trying to solve here?